Awkward Situations

Today was one of those days full of weird, indelicate situations - the kind of stuff people face everyday, but it never comes up in Dear Abby, so we don't know what the hell to do about it.

• A lovely young mother in track pants leaned over her baby's stroller to adjust something and exposed fully half her ass, apparently without realizing it. I'm not talking cleavage, I mean half a cheek on either side and a full two inches of butt floss in between. Should you tell someone when this happens? Or just hope that sooner or later they notice a slight breeze and start wearing a belt?
• At the coffeeshop, I noticed a tiny spider crawling in an elderly woman's hair. Again, is this something you should share with a stranger? I didn't want to say, "Excuse me, ma'am, there's a spider crawling on your head" and risk her being an arachnaphobe who would jump up screaming bloody murder, dousing herself with hot coffee. It wasn't a big spider. And of course you can't just smack the spider to the floor without warning, that would just be weird. And saying "You have something in your hair" isn't kind, 'cause as soon as the person reaches up they'll find out it's a spider.
• Also at the coffeeshop, there's a man...or should I say woman...who is clearly not quite either. I honestly can't tell if he is pre-op, or if she is post-op, or if this person isn't "op" at all but just rather confused. I'm rather confused. The problem is, you want to be gracious and polite without seeming overly gracious and polite. You don't want to come across all, "Hi! I'm exaggeratedly cheerful to mask the total awkwardness!" And the whole time, Boy George's "The Crying Game" is looping through your head and you wish he/she would just hurry up with the frickin' latte so you don't have to study his/her bosom, trying to figure out if it's silicone or rubber.